Not applicable.
1. Field of the Invention.
The present invention relates generally to a side bar inserter, and more particularly, but not by way of limitation, to an apparatus for inserting a side bar having a bar portion and a flanged end in a side face of a concrete slab formed by a slip form paver.
2. Brief Description of the Related Art.
Roads and runways are constructed of large expanses of concrete pavement, and therefore, are generally comprised of several slabs of concrete formed adjacent one another. When forming one slab of concrete adjacent to another slab of concrete, the adjacent concrete slabs are typically tied together with a plurality of steel side bars (also known as tie bars) spanning between each of the adjacent slabs. The side bars are inserted into the side face of the initially formed concrete slab so that a portion of the side bars extend a distance from the side face of the concrete slab. The adjacent slab is then poured thereby encompassing the extended portion of the side bars.
When a slip form paver is used to form the concrete slab, the side bars are often inserted into the side face of the concrete slab as the concrete slab is being formed. Slip form pavers are self-propelled machines having spaced vertical side forms and a screed extending between the side forms. The screed is supported by a frame and screeds the concrete deposited on the road bed ahead of the advancing slip form paver. The pressure exerted on the concrete by the screed and the side forms is sufficient so that the contour of the concrete slab is maintained as the slip form paver continues to advance down the road bed.
Side bars have conventionally been straight metal rods having a length sufficient so that half the side bar extends into one concrete slab and the other half extends into the adjacent concrete slab. To this end, numerous devices have been proposed for use in conjunction with a slip form paver for inserting such side bars into the side face of a concrete slab.
However, a two piece side bar has been introduced in recent years. The two piece side bar includes a first section that is inserted into the initially formed concrete slab and a second section that is connected to the first section so as to extend from the initially formed concreted slab prior to forming the adjacent concrete slab. The first section has an open threaded end which is adapted to threadingly receive one end of the second section. The threaded open end of the first section is also provided with an outwardly extending flange which acts to limit the depth of insertion of the first section into the concrete slab to where the threaded opening is substantially flush with the side face of the concrete slab.
When employing the side bar inserters of the prior art to insert the first section, problems are encountered due to the existence of the flange of the first section. That is, the side bar inserters of the prior art are provided with a bar receiving chamber in which a straight side bar will lie flat and in turn be inserted into the concrete slab in a normal relation relative to the side face of the concrete slab. However, when the first section of the two piece side bar is placed in the bar receiving chamber, the flange causes the bar portion to lie at an angle with respect to the side face of the concrete slab. As a result, the first section will be inserted into the concrete slab at a downward angle which will result in the second section extending at an upward angle.
To this end, an apparatus is needed for inserting a side bar having a bar portion and a flanged end in a side face of a concrete slab formed by a slip form paver which will accommodate the flanged end and thus permit the bar portion to be disposed at a selected relationship relative to the side face of the concrete slab. It is to such an apparatus that the present invention is directed.
The present invention is directed to an apparatus for inserting a side bar having a bar portion and a flanged end in a side face of a concrete slab formed by a slip form paver. The apparatus includes a frame having a side bar receiving chamber defining a travel path. A slide pin is extendable through at least a portion of the side bar receiving chamber so as to engage the side bar and cause the side bar to be driven from the side bar receiving chamber along the travel path. A guide member is connected to the frame and movable between a first position wherein the guide member is positioned to vertically support the bar portion of the side bar in a selected relationship with respect to the side face of the concrete slab and a second position wherein the guide member is retracted from the travel path of the side bar to permit the flanged end of the side bar to travel past the guide member along the travel path unimpeded by the guide member.
The features and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings and appended claims.